LANDSCAPE FORESTRY 



213 



perfectly flat horizon very rare. But probably few objects 

 under 100 feet in height, such as trees in general, have any 

 definite effect at a greater distance than a mile. At that 

 distance the angle formed by the height of such objects, and 

 the point of observation, is so small, that the difference 

 between their outline and the horizon lies in the former 

 being broken and irregular to a greater extent than the 

 latter. Even this distinction disappears when a large block 

 of unbroken woodland forms the back-ground ; for the tops of 

 the trees being on practically the same level, the line they 

 form at a distance has much the same effect as a flat ground 

 surface. Trees or woods at such a distance, therefore, should 

 be sufficiently broken and varied in height, to render a dead 

 or uniform level impossible. In many cases narrow belts of 

 tall trees have been planted to form back-grounds to park 

 scenery, the result being that not only are their tops on a 

 more or less dead level, but the gradual loss of their lower 

 branches has rendered visible a narrow streak of sky between 

 the crowns of the trees and the ground level. Such an effect, 

 which is more or less characteristic of many of Brown's 

 inevitable circular belts, is a great deal worse than that 

 produced by absolutely open country, and no hesitation 

 should be felt about breaking up such belts whenever they 

 occur. 



But on hilly or undulating ground the effect produced 

 by trees or woods is seen at a much greater distance than 

 on flat ground, although it still diminishes and disappears as 

 the distance increases. The best effect is probably produced 

 on a hillside or bank from a quarter to a half mile away, on 

 which the outline and character of every tree can be seen 

 at a glance, and where the effects of sunlight and shade vary 

 with the season and time of day. Here again, however, 

 density and uniformity destroy a great many of the finer 

 effects by producing a flat surface, on which nothing but the 

 smaller twigs are visible as a homogeneous mass, varied only by 

 those differences in the height and shape of the crowns which 

 occur with individuals or different species. But to obtain 

 really fine effects the trees must stand singly or in small 

 groups between the larger masses, which ought to crown the 

 summit and blot out the sky-line to a greater or less extent. 



